Morphological control of three-dimensional carbon nanotube anode for high-capacity lithium-ion battery

Abstract

In this paper, we report the results of modulating the processing conditions (mainly, temperature) of a two-step method consisting of sputtering deposition of a Ni catalytic layer and chemical vapor deposition (CVD) of carbon nanotubes (CNTs) on a three-dimensional (3D)-structured Cu mesh to control the morphology of CNTs for advanced Li-ion battery (LIB) applications. We disclosed that CNT growth at a low temperature (700 degrees C) produced small-diameter CNTs (CNT_S) with an average diameter of similar to 20 nm, while that at a high temperature (750 degrees C) produced largediameter CNTs (CNT_L) with an average diameter of 200-300 nm. The high-resolution transmission electron microscopy (HR-TEM) and Raman analyses manifested poorly crystalline CNTs for both samples. CNT_S showed a specific capacity of 476 mAh g(-1) , which is similar to 176% superior to that of CNT_L (271 mAhg(-1)) and similar to 128% higher than the theoretical capacity of the state-of-the-art graphites and recently reported nanostructured carbon-based anode materials. (C) 2018 The Japan Society of Applied Physics